Q. If 25 A current is drawn by 220 V motor and back emf produced is 80 V, the value of armature resistance is
A) 56 $\Omega$
B) 5.6 $\Omega$
C) 0.56 $\Omega$
D) 0.5 $\Omega$
Explanation
(b) $i = \ \frac{V - E}{R},\ R = \frac{V - E}{i} = \frac{220 - 80}{25} = 5.6\ \Omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.